GoPro Dual Camera Battery Charger max amps/volts?

I have the GoPro dual camera battery charger and I'm looking at getting an external battery brick to charge from whilst out and about, and these external bricks provide power at different rates (5V2.4A, 5V2.1A, etc.), so I'm wondering what is the maximum volts/amps that this dual battery charger can take?

Re: GoPro Dual Camera Battery Charger max amps/volts?

That 5V 2A recommendation is for charging the GoPro itself, not the dual battery charger... right? I couldn't find any documentation that listed what the dual battery charger itself can take as an input.

The dual battery charger states that you can connect it to the Supercharger for faster charging, so I would assume that it must be able to charge at the higher volts/amps that the Supercharger provides (5.1V 3A, 5.5V 3A, 12V 1.67A) and if so... that would mean it can support for example a power bank at 5V 2.4A since that is less amps?